Role of Airway Smooth Muscle (ASM)
Airway smooth muscle is located within the walls of airways in the lung. There is typically an increase in the amount of airway smooth muscle in the lungs of patients with asthma. This increased airway smooth muscle mass has the potential to increase airway responsiveness and constriction in response to external stimuli, such as dust, allergens, cold air or stress. The excessive and inappropriate constriction of airway smooth muscle is recognized as a predominant feature of asthma, and therefore makes the airway smooth muscle a key target for drug therapy.
Although current medications are reasonably successful in controlling inflammation and contraction of airway smooth muscle in the majority of patients with asthma, some patients with severe persistent asthma continue to suffer from excessive bronchoconstriction that is integral to an asthma “attack” (exacerbation). Reduction of airway smooth muscle helps reduce the ability of the airways to narrow in response to a trigger, thereby providing a therapeutic benefit for patients with severe asthma.
